Over the past several years, Bleiweis and co-workers have isolated and partially purified antigenic glycerol teichoic acids from the cell walls of Streptococcus mutans, Group II and the cell membranes of S. mutans, Group 1 organisms. The objective of our project is to isolate and purify large yields of these antigens to chemically and physically characterize each, determine biochemical structures (i.e.; type of phosphodiester linkage, chain length, nature and extent of glycosidic substitution, and type of anomeric linkage) in each case, determine the nature of haptenic groups, and demonstrate the group-specificity of each antigen. We plan, also, to determine the biochemical and immunochemical structures of the S. mutans, Group II cell-membrane teichoic acid antigen, if it is distinct from the above antigens. In this manner, we hope to determine the immunochemical definition of S. mutans, Group 1 and II, and to provide data necessary for a reliable serologic classification of the many S. mutans strains.